Method of burning fuel.



E. F. SIEWART @L R. P. PERRY. METHOD or BURNING FUEL.

Y APPLxpATl'oN FILE'D mmm?, 1914. 1913549421 D Patented Am., 6, MM5.

3 SHEETS-SHEET 1.

@W7 3 mju-fa who@ E. F. STEWART @L R; P. PERRY..

METHOD 0F BURNING FUEL..

APPLICATIOMFILED MAR. 1T,fl9-l4.

Patented Apr., m5.

s SHEETS-SHEET 2.

E. F. STEWART @L R. P. PERRY.

METHOD 0F BURNING FUEL. APPLICATION msn MAR. n, 191.4.

'Patented Apr. 6

a SHEETS-SHEET a.- Y,

Maak/m* 7g2/f @my Swivel/Wow spectively,

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JEnsEY,l As'srenons To N. Y., conroaATroN or VIRGINIA.

METHOD or nunmncf FUEL.

T0 all whom -zt may concern.'

yBe it kuownthat we, EDWIN R-.STEWART and RAY POTTER PERRY, citizens of the United States, andresigdents -of Woodcl-i-ff, New Jersey, and Montclair, New Jersey,- rehave invented certain new and useful Improvements in-Methods of Burning Fuel, of which the following is aspecl# ication. I

This invention relates to new and useful in the commercial rltihzation powdered or minutely subdivided state,- such las coal tar pitch, asphalt, mineral pitch,res inous by-products, mineral oil residues, or other, fuel materials, which have the 'characteristic of becoming soft and adherent when heated -to `comparatively lowtemperatures and therefore cannot be'handled successfully by existing devices which handle pulverized coalas a fuel.

Wherever we use low temperatures this patent application we refer and limit ourselves to temperatures of from say 7:0o to 400 F., the temperatures within such range being low in comparison with that of the heat .radiating from a furnace burning pulverized fuel.

In burning pulverized coal, it is customary to reduce it to `a ,suitable neness and blow it, mixed withl air, as a carrier-and for combustion, by'means of a fanv or blower through a plain metal. nozzle l into the furlnace where it is burned. Ordinarily the metal nozzle becomes heated by radiation from the furnace, but does not attain such temperature as will soften and-make adherent any particles of the pulverized coal which may impinge upon the inner of the nozzle. made to deliver pulverizedcoal tar pitch or resinous fuels through such a plain and heated nozzle, .it is found that such minute .particles of this material as are impinged upon. the interior surface of the nozzle are so' softened as to 'become `adherent thereto, and gradually accumulate in a coke-like( mass in the bore thereof. As a result-the continuous vdelivery of the pulverized fuel, to the furnace is interferedw-ith seriously, and the nozzle may be completely choked by the a'ccumulated-coke. This explainable by the Specicaton of Letters Patint.

the terme comparatively surface- If, however, an attempt-1s lurally.

fact that which may be hard enough to grindwand lptilverize at -normal atmospheric; temperatures are `still softened and becomeadherent at tempera-turesdof, say as low. as M002 F., which would be insuicient to soften coaly andmakeit adherentunder the conditions of use.

Our myention consists 'in the vapplication ofafcoolmg medium toE the delivery noz'zle and in addition thereto other features of `oruyapparatusas hereinafter described which as pulverized fuels, which have a great in-A i l Patented Apr. 1915. .Appueauonnleenarh 17, 1914. .seriamqaama i ran LsTATEs PATENT. orrion.

E STEWART, or woonomrr, AND RAY roTTER PERRY, or'nonfronnrn, NEW BARRETT MANUFACTURING: GOMPANY,-OF NEW YORK,

herent advantage overpulverized coal due tothe 'fact that pitch,as an example, contalns less than one quarter of one per cent.

of ash, whereas pulverized coal contains or' dlnarily upward of ten per cent. Ixtsis thus evident thatour invention is of especial importance for use 1n varlous metallurgical burned pulverized coal is a serious disadvantage, makihg it necessary either to provide special means for removing and handling the ash which is usually'detrimental to 4material and process, or else to use oil or gaseous fuel as an alternative, either of which may relatively increase manufacturing costs, as compared with the new fuels herein described. A

."Vherever we use the terms artificial or artificially in this patent application we refer and limit ourselves to the use of these words as expressingthat the deviceor arrangement'is made or contrived by art -or produced or modified by human skill and labor' inlopposition to such occurring nat- We are describing herein three special types or constructions of apparatus adapted to accomplish the 4primary object of our 1n-` yention, whichA consists primarily in the positive or artificial cooling of a nozzle for y'delivering these pulverized fuels to a furprocesses Where the presence of ash from nace, but we do not lconfine ourselves to cure the essential feature of artificially coolthese three types, and may employ any other suitable and locally accessible means to secessory apparatus which maylassist in preventing the radiation of heat from the furnace to said fuel nozzle, all for the Iobject and purpose as hereinbefore described.

The invention consists further in various details of construction, and in combination and arrangement of parts, which will be hereinafter fully described, and then specifically'defined in the appended claims'.

Our invention is illustrated in the accompanying drawings, which with the letters of reference marked thereon, form apart of this application, and in which drawings `similar letters of reference indicate like parts in the views; in which- Figure 1 is a central through our apparatus, as applied to a boiler furnace, parts being "shown in elevation; Fig. 2 is a vertical longitudinal sec- 'tion lofthe apparatus itself, showing one form ofnozzle construction with an vorifice.

or baffle plate, whereby our primary invention of artificially coolingthe nozzle walls plished; Fig. 3 isa rear elevation of this form of nozzle construction, the furnace wall not being shown; Fig. 4 is an elevation and partial section of the orifice or baffle plateI showing circulating pipes for .the cooling fluid; Fig. 5 is asectionaldetail 'of a combined form of the nozzle and orifice plate; Fig. 6 is a sectional detail of the furnace wall with our nozzle and orifice plate shown as al modified `form ofconstruction, wherein our primary invention offartifi.- cially cooling a pulverized fuel nozzle is accomplished by theco'mbined effect ef. cool air and liquids, in which the air so used is discharged outside the furnace; Fig. 7 is an end elevation of Fig.'-6'certain parts being broken away; Fig. 8 is a modified form of the general construction shown in Fig. 6 in which the air for cooling the nozzle is discharged into the furnace through the orifice plate; Fig. 9 is an end 'elevation of the noz` zle and orifice plate construction shown in Fig. 8; Fig.y 10 isfa modified construction of the nozzle shown in Fig. 2 wherein the cooling liquid is circulated around the nozzle from a spray or shower pipe above; and

Fig. l1 is an end elevation of the nozzle and 1 orifice plate construction shown in Fig. 10. We now describe three'preferred forms of apparatus whereby the object of our invention as embodied in the artificial "cool ing of a pulverized fuel 'nozzle may be'successfully accomplished or wherein this cooling may beapplied to other necessary parts, as a further means of protecting'the nozzleI vertical section i by means of a circulating fluid is accom-- It may be of advantage with some of from the radiating heat of the furnace, and all for the object and purpose hereinbefore described.

tion. To maintain continuousfeeding :of these adherent fuels into the furnace, We have discovered that the heat of the interior surface of thenozzle wall must not exceed average normal air and water temperatures by more than about 330 F., depending on the adherent temperature 'of the particular fuel employed, and this is accomplished by artificially cooling the wall of the nozitle Reference now being had to the details of i .carrier and necessary agent for its combuswith any fluid that maybe circulated within an annular outer casing or jacket, shown as C, such `as air, water, rine, oils, ,or` a fiuid that will absorb and carry away the heat radiated from the furnace vsufficiently to maintain the temperature of the nozzle wall f below the adherent-temperature of the fuel'. As a further means-of preventing heat radiation. to the nozzle A, weniay provide as apart of'this special apparatus, a chambered b oxor plate, as L, having a'central orifice, as at G, to be mounted-when required in the front .wall of the furnace withjits orifice registering with the opening of the nozzle, and cooled by the'circulation of any designated fluid that may be supplied to'the chamber from a suitablesourceby the inlet pipe, as H, preferably at the top of the plate, and discharged at the opposite side of the partition J, through the pipel I, thus giving complete circulation around the orifice and within the chamber of the plate.

The annular jacket of the 'nozzle is also supplied with cooling liquid, air or vapor from a suitable source, as by the piper D,

where a liquid is used, this pipe extending' within the jacket of the nozzle, preferably' ing the jacket tangentially as shown by R,`

at the point T, circulatin around the-nozzle f within the jacket and. ally discharging lfrom the opening V, at the extreme end of j the nozzle.

l the uels hereinbefore described, and where 4a fiquid is used for artificial cooling, to com-130 misma-1 bine the jacketed nozzle and-"chambered orifice plate as one piece of apparatus,

shown in Fig. 5, 'wherein thewalls off the nozzle and late are so attached that'cn'e common cooing chamber will produce the desired effect, 1n lwhich case clrculation fis maintained by means of the supplyfpipe' 'zfurnace throlugzjhv the orifice plate a'dffthe're-l j iin mix it with the additional air and'fuel 'minates the discharge' outlet V.

j the top ofthe no zz from which the-cooling liquid is s raye and the discharge pipev E, .the plpes D land J being omitted. In other cases" owing to peculiar characteristics of nsome-'cf these fuels, it will be found' to be vdesirablewhere air or vapor is used as a cooling" agent, to 'conduct itfrom the nozzle jacketninto the entering through the nozzle. A form yof construction to permit this effect .is shown in Fig. 8, wherein the end wall of thejacket at the fire end is removed allowingv the cooling air to enter the furnace, and which e11- A `modified construction and jacket is eliminate and the supply-and dis-l tribution of the cooling liqui connected` to a suitable source of suply allowed'to fiow `over the outer sur acevo'fjthe exposed section of the nozzle, the, extreme end being provided with a vstop ange s othat thewater is collected and disposed 'of by the pan Z and the conductor ipe E1, thus in some specific cases iving t e same. coolin effect asthe jacket ereinbefore de-l While we I'have shovn a number of modificationsI in the 'form' and `details ofconstruction for our-apparatus, 'it will be understood that this variation in form and manner of application is to a certain extentV made `necessary asa means of successfully utilizingI all of the fuels hereinbefore described, by reason of their' relatively varying and specific character, and that all the modiications of our apparatus herein described lare ,intended to coperate as an essentialy becoming adherent at comparativelyl low yfio temperatures.

I aving thus fili,

1. In the consuming ofv pulverized fuel which 4,softens so as to become adherent at i a 4telst'iferature below 400 F., the lmethod v l method for j obtaining the necessary circulation. of cooling liquid aroundl the nozzle wall 1s shownv in Fig. 10 and 4Fi 11, in ywhich casel the D xilaintaned b the perforated ipe 1'exten 'ng a ong y 11g parallel to its axis, andv .ture of lthe surfaces of sai described our invention,v what lwe claim and desire to secure by Let- `whichcomme fin'cooung .the Aeurams with which such'fuel-makes ycontact in passing l intoltlie zone' 4'of combustion, so as to main-v tainl 'their' temperature below that at which' such vfuel beconis adherent. p

2. `In -the'burii'ng of pulverized fuelwhich softens so asto become adherent ata lower temperature than 400 F., the methd which consistsiiirfdelivering said fuel in" a stream into the placexof combustion, and in "circulating afcool'ing 'Huid aroundl and'adj'aent said stream "so astel maintain the temprature of thelparticles of fuel below ,thatvat which they'wo'uld become adheren't 3;;In feeding to a furnace a pulverized fuel which softens at a critical temperature below 400"v F., so as to become adherent, the

method which consistsl in* delivering ,said` fuel with a commingled current of combustion-supportinggas, and meanwhile maintaming. the particles of fuel in said current' below said critical temperature.

. 4.,'In feedingto a furnace a vpulvieriz'ed fuel which softens so as to ybecome adherent at a critical temperature below 400 F., the method whichconsists in ldelivering said .fuel ina streamwith combustion-su porting gas, confining said stream against ateral expansion, and maintainin the temperature of the confining meansbe ow such critical degree.

1- A5. In theioperation of feeding into the combustion chamber of a furnace a pulver- 4ized fuel which softens so as to become adhei-ent at a critical temperature less than 400 F., the method 'wh1ch consists in deliverin said fuel ina blast through a conduit w ich is subjected to a. much higher tem erature than 'said criticaly degree, and at t esame time maintainin the temperawhich such stream of fuel makes contact belovf sid critical temperature. n

'fuel which softens so as to become adherent conduit with feedingqto a furnace "pulverizd I at a critical temperature less than 400 F.

the method which consists in carrying sai fuel through a chamber which is e'x osed to a zone of heat greatly in excess o said critical temperature, and in maintaining the.

surfaces with which 'said fuel makes contact at 'all times below' said critical'temperature.

l 7. The metho'clof burning solid f uel which softens so asto become adherent at a tem erature below 400 F., which consists in rst lpulverizing the same, then delivering it with a blast of combustion supportlng gas through a restricted space to the point of combustion, and meanwhile maintaining the temperature in said space below that at which such fuel softens lso as to become adherent.

. 8. The-method ofrburning a solid fuel which softens so as'to become adherent at` a temperature-below 400? F., which consists porting gas'through aV chamber tothe point of combustion, and meanwhile maintaining the temperature within said chamber below .that atwhich said fuel softens so as to be'-l come adherent.

9. The method of consuming a solidfuel which softens at a critical temperature be-v low 400 F., so as to become adherent, which'l consists in first nely pulverzing said fuel,

' then delivering the same in a current of com- :bustion supporting gas to the point of combustion, and meanwhile maintaining the vparticles of fuel insaicl'current below said bf .New York andI State of New Yorkthis lfltli day of March 1914..

f- EDWIN F. STEWART.

RAY POTTER PERRY. 

